In the classic film "Bullitt," Steve McQueen had his hands full hustling a green 1968 Mustang GT fastback as he tried to ditch a duo of shotgun-wielding thugs in a black Charger. The Mustang was a performer, but it required performance and suspension upgrades for its high-flying stunt work. The same goes for today's Mustang, a platform that's proven popular with the aftermarket and club-racing set during its 25-year tenure.

In an effort to maintain interest in the current car while the 2005 was under development, Ford launched a series of retro-themed special models, including the Bullitt and the even more potent Mach 1. The latter incorporates a special 4.6-liter V-8 with DOHC four-valve heads and unique "shaker" intake, improved suspension, and better rolling stock. It outguns a standard GT, but we recently sampled a raucous Mach 1 from the supercharging experts at Vortech that nearly knocked off our Nomex socks--yet still would work as a daily ride.

Vortech's High Output centrifugal supercharger system packs in the fuel and air. The smog-legal blower delivers 10psi boost cooled by an air-to-water intercooler that Vortech claims delivers a 179-horsepower gain with 100 pound-feet more torque output--all on premium-unleaded fuel. Vortech includes a high-flow fuel pump, larger fuel injectors, and a 90mm mass-airflow sensor all kept in check via a reprogrammed ECU. Power is strong (Vortech rates it at 484 horses) yet surprisingly linear across the powerband. This is noteworthy, as most centrifugals are known for peaky top-end power.

In our acceleration tests, the Vortech Mach 1 humiliated a stock Mach with a sub-12-second quarter mile on Toyo radials. If the stock suspension were retained, most of that power would've gone up in smoke, thus much credit goes to the well-sorted suspension system from Griggs Racing. Normally considered road-racing ware, the Griggs GR-40 setup did an amazing job under acceleration, braking, and cornering conditions, thanks to its unique torque-arm arrangement. Front upgrades include tubular A-arms, tubular "K" member, bump-steer kit, coil-over shocks with Koni struts, relocated anti-roll bar, adjustable caster plates, and special alignment specs. Out back, a custom torque arm, Panhard bar, unique rear control arms, and subframe connectors team with special bushings and Koni coil-over shocks to deliver high-limit results without a punishing race-like ride.

Tuners: 2003 Vortech Mustang Mach 1

Halibrand Cobra III 18x9.0-inch wheels wrapped in Toyo Proxes RA-1 tires contribute to a Mustang with nearly neutral handling (versus the understeer-prone stock setup) that's substantially more predictable when pushed to the limit. At $4700, the suspension may seem expensive, but the GR40 kit is possibly the best aftermarket Mustang suspension we've ever tested.

Our only criticism is with the racer-boy door decals on this test and development car that would give away your game. Regardless, Viper and Z06 owners, beware.